If is used when you want to conditionally run a command. It has the form of if condition [ command ], or if this-is-true [ then run these commands ]. If the condition is True, the command will run. If the condition is False, the commands will not run, and if the value resolves to anything other than true or false, an error will occur. For example, ask turtles [ if time = night [ sleep ] ] would mean “if it is nighttime, then the turtles will go to sleep”. Multiple commands can be executed, as long as they are all contained within the same [ ].